6.54.3 Can you answer these questions?

6.54.3.1 How can I get a complete circle with labels around the circle

https://tex.stackexchange.com/landing/r/digest?cta=question&id=563161

I got this semi-circle for illustration and I need the two mouths to touch each other like exactly a circle still with metric label like what I have in the MWE 
% !TeX program = lualatex 
\documentclass[... 
[circles] [luamplib]
 

asked by Daniel James https://tex.stackexchange.com/landing/r/digest?cta=user&id=104402 1 vote

6.54.3.2 Command \upshape invalid in math mode

https://tex.stackexchange.com/landing/r/digest?cta=question&id=563055

The problem I meanwhile solved myself, but the question remains. I forgot a \text{} wrapper in a \flalign* env and got the mentioned error. Now, the math part isn't wrapped in \text{} (duh) which ... 
[amsmath] [flalign]
 

asked by Hauke Reddmann https://tex.stackexchange.com/landing/r/digest?cta=user&id=144976 1 vote

6.54.3.3 Context: How to do full-page figure with proper orientation and captions in opposite page?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=563293

I've searched in ConTeXt manuals and here, but couldn't find a way to achieve these 4 requirements altogether: 
Place a figure as full-page figure (works without other requirements) 
Change orientation ... 
[floats] [captions] [context] [layout]
 

asked by JosA~(c) de Mattos Neto https://tex.stackexchange.com/landing/r/digest?cta=user&id=178125 1 vote